Crossbar switch mechanism



Dec. 10, 1946. c. GILLINGS ET AL CROSSBAR SWITCH MECHANISM Filed DeC. 4, 1943 INVENTORS GHARL GILLINGS LAWRENCE HN MURRAY BY ATTORBEY Patented Dec. 10, 1946 CROSSBAR SWITCH MECHANISM Charles Gillings and Lawrence John Murray, Liverpool, England, assignors to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application December 4, 1943, Serial No. 512,889.

In Great Britain January 21, 1943 3 Claims.

The present invention concerns crossbar switches of the type in which in order to effect the selection of a desired contact set, a preparatory operation is effected for the row of contact sets in which the desired contact set is located and an operating and hold operation is subsequently effected for the column in which the desired contact set is located to effect the operation of the desired contact set while permitting the preparatory operation to be repeated if required for the operation of *other contact sets in the same row.

In one form of such switch there is provided for each of the columns a holding bar member operable under control of an electromagnet, while for each pair of adjacent rows of contact sets there is provided a selecting or preparing bar member which carries a number of flexible or flexibly mounted selecting fingers corresponding to the number of vertical columns, and which is operable under control of a pair of electromagnets to move the selecting fingers into position adjacent the contact sets of either of the pair of rows involved.

A IOU-point switch of this kind is provided with ten rows and ten columns of contact sets and with five two-way horizontal selecting bars each of which will carry ten selecting fingers corresponding to the ten vertical holding bars which will be required and at each of the fifty intersection points two sets of contacts will be provided. In order to select a given set of contacts the associated horizontal bar will be twisted in a direction to bring its selecting fingers opposite the contact sets of the particular row of ten in which the required contact set is located and the subsequent operation of the vertical bar common to all the sets of contacts in the same column as that in which the required contact set is located will operate this contact set due to the fact that this will be the only one in the column having a selecting finger interposed between itself and the vertical bar.

.When this contact set has been operated the horizontal bar may be released, but the contact set operated will remain held from the vertical holding bar. Subsequently a second or further set of contacts can be operated in similar manner provided it is in a different column to the one already operated, but it may be located on the same row.

With switches of the type referred to, in order to select the desired contact set it is necessary to provide means to determine the desired preparatory operation to be effected (e. g. the desired horizontal magnet) as well as means for determining the desired operating or holding operation (e. g. the desired vertical magnet). It has been proposed to employ a uniselector switch separate and distinct from the crossbar mechanism to select the desired horizontal magnet in response to received impulses and the object of the present invention is primarily to avoid the necessity of providing a plurality of horizontal magnets 01' their equivalent and in addition the invention provides means whereby a crossbar switch mechanism can be operated directly by impulses.

According to one feature of the invention a crossbar switch is provided in which desired sets of contacts are operated due to initial preparatory operations corresponding to the rows of contactsets in which the desired contact sets are located respectively and the subsequent operating and holding operations corresponding to the columns of contact sets in which the desired con tact sets are located respectively characterised by the provision of a single step-by-step electromagnetically operated mechanism arranged to efiect by mechanical linkage initial preparatory operations for a plurality of operating and holding operations.

According to another feature of the invention a crossbar switch is provided having parallel bars for effecting initial preparatory operations and having other parallel bars for effecting operating and holding operations crossing said first bars in which a shaft extending parallel to said other bars is arranged in each of a number of different angular positions to select one of said first bars to effect an initial preparatory operation so that when one of said other bars is operated after one of said first bars a contact set associated with the intersection of said bars is operated and the shaft is free to be reset for the selection of another contact set.

One example of the invention is illustrated in the accompanying drawing comprising Figs. 1-4, of which Fig. 1 shows a partial front elevation of a -point crossbar switch of the type described with an impulse responding uniselector mechanically coupled thereto. Fig. 2 shows a view through the line AA (Fig. 1), while Fig. 3 shows a view through the line BB (Fig. 1). Fig. 4 shows a perspective view of part of the mechanism of a typical crossbar switch, further information about which can be obtained from our application Serial No. 476,898, filed February 24, 1943, now Patent No. 2,364,706, dated Dec. 12, 1944.

Referring now to Fig. 1, the crossbar switch is provided with five horizontal bars such as H, 2| and 23, and ten vertical bars such as l2, the latter being operated by the vertical bar magnet armature Id. The contact sets are indicated generally by the rectangles such as [3. The pair of contact springs at the intersection of the horizontal bar II and vertical bar l2 are shown in Fig. 4 where the contact spring sets are designated 24 and 25, the corresponding spring finger on the horizontal bar being designated 26.

As regards the operation of the horizontal bars, the shaft it of the uniselector I5 is rotated in response to a train of received impulses and thereupon drives shaft l1 through suitable gearing IS in such manner that for eleven steps of the uniselector the shaft I6 makes a complete revolution. It will be seen from Fig. 1 and Fig. 2 that there are ten pins l-ll arranged in a spiral on the shaft l1 and the arrangements are such that in response to a single step of the uniselector the shaft (6 rotates sufliciently to move the pin l into a position where it will rock the arm 19 aifixed to the end of the horizontal bar II thus causing the latter to rotate through a given angle and to bring all the operating fingers associated with it into their respective engagements.

At the second impulse, shaft H makes a further step and moves pin I out of engagement with arm I9 thus restoring horizontal bar I to normal under pressure of a convenientl mounted return spring 21. At the same time pin 2 moves into engagement with arm 20 afiixed to the second horizontal bar 2| thus operating this bar in similar manner as for bar II. At the next impulse, bar 2| is restored and bar 23 is operated by pin 3. and arm 22 and so on. On the sixth impulse arm I9 is again rocked, but this time by pin 6 in the opposite direction to its operation by pin I. This rotates arm I! in the opposite direction to put the operating fingers into engagement with the other set of springs associated with arm II. Similarly the seventh, eighth impulse and so on respectively cause pins 1, B and so on to operate bars 2|, 23, etc.

At the end of the digit dialled the appropriate pin on shaft I1 is in engagement with its appropriate arm and the appropriat horizontal bar is therefore operated in the correct direction so as to prepare all circuits in the level required for the selection of an outlet. When this is chosen the associated vertical magnet operates and operates the correct spring set.

The uniselector thereupon homes and the shaft I! thereupon restores to its normal condition for another call.

. It will be understood that the wipers and banks of the uniselector may still be used for other functions as required.

The invention may be applied for instance to the group selector described in our application Serial No. 512,888, filed Dec. 4, 1943. It would necessitate the control equipment being individual to the group selector which is usually the case and would in the case of the crossbar switch whose preparatory operation is determined by the received impulses eliminate the wiper which selects the prepare magnet for such switch as well of course as the prepare magnets themselves.

It will be understood that the invention is not restricted to application to a group selector or to an impulse responding switch. For instance where the prepare operation is effective as a result of hunting for an idle or marked line, a wiper of the uniselector mechanism controlling the prepare bars can be arranged to test the condition of contacts marked by the lines being tested While the magnet of the uniselector steps automatically to advance the wipers. The arrest of the wiper on the line selected corresponds of course to the deflection of the horizontal bar and of the prepare operation appropriate to the connecting up of said line.

What we claim as new and desire to secure by Letters Patent is:

1. In a crossbar switch, lateral bars and longitudinal bars so arranged that each lateral bar intersects all of the longitudinal bars, two sets of electrical contacts for each such intersection, each of said bars having a normal position, means mechanically linked with allof said lateral bars and selectively operated to move any desired one of the lateral bars in either of two directions away from its normal position, means for moving any one of the longitudinal bars away from its normal position, and mean whereby the movement of any one of said lateral bars and any one of said longitudinalbars away from their 'respec tive normal positions is effective to operate the two contact sets for the intersection of those bars selectively in accordance with the direction that said one lateral bar is moved away from normal.

2. In a crossbar switch, a plurality of parallel bars each having a normal position, mechanism common to said bars operated to engage and move any desired one of said bars to either one of two oif-norm'al positions, a plurality of parallel bars arranged in a direction transverse to said first bars, each of said last bars having a normal position, means for moving any desired one of said last bars to an off-normal position, a plurality of contacts sets, and means whereby one of said sets is operated by the movement of one of said bars to an off-normal position whenever such movement occurs at a time when any nonparallel one of said bars already occupies an off-normal position.

3. In a crossbar switch, lateral bars and longitudinal bars so arranged that each lateral bar intersects all of said longitudinal bars, each of said bars having a normal position, electrical contacts at each intersection of said bars, a select rod having helically arranged projections, two projections for each lateral bar, means for rotating said select rod to cause one or the other of any pair of projections to act on a corresponding lateral bar, thereby to displace said bar in one direction or the other from its normal position, means for displacing any one of the longitudinal bars from its normal position, and means responsive to the displacement of said lateral bar followed by the displacement of said longitudinal bar for operating a corresponding set of contacts at the intersection of said bars.

CHARLES GILLINGS. LAWRENCE JOHN MURRAY. 

